Floating roof



Sept. 18, 1951 J, W, ALLEN 2,567,920

FLOATING ROOF Filed 0G12. 6, 19.45

Patented Sept. 18, 1951 FLOATING ROOF John W. Allen, Chicago, lll., assignor to Chicago Bridge & Iron Company, a corporation of Illinoia Application October 8, 1945, Serial No. 620,777

1 Claim.

This invention relates to a oating roof and more particularly to a floating roof having an annular deck portion primarily supported by a central pontoon and stabilized by an annular pontoon.

The invention is illustrated in the drawings, in which Fig. l is a plan view partly in section of the roof; Fig. 2 is a fragmentary sectional elevation-thereof; and Fig. 3 is a sectional view taken along the line 3-3 in Fig. 1.

The roof comprises a central pontoon II which supports an upwardly sloping annular deck portion I2, which in turn is attached to a point well below the inner face of the annular pontoon I3.

As will be observed, the deck portion I2 is made of metal and may be made continuous with the top Il of the central pontoon. The buoyancy of the central pontoon is made such as to provide normally an annular gas space I5 away from the center of the tank. Any suitable means of venting this space, as indicated diagrammatically at I6, may .be employed.

The annular pontoon I 3 is provided with an inwardly sloping upper face I1 and a vertical inner face Il which joins the deck I2 to form a trough Il. It will be observed that all water drains toward this trough, from the center pontoon, from the deck, and from the annular pontoon. A drain or a plurality of drains 20 may be provided so that any water received on the surface of the deck will flow into the liquid. Inasmuch as the center pontoon carries its own weight and that of the deck, the deck will be stable and tight and at the same time provide good drainage to the outer pontoon.

The vapor space is cut to a minimum by placing it at a point intermediate the center and the outside of the deck.

The center pontoon will carry considerable pressure under the deck without flexing so that the expansion of gases can be five or six times normal before any venting occurs under the outer pontoon.

A section 2| of the annular pontoon may be omitted adjacent the drain so that tipping will normally occur in that direction. This may readily be accomplished by omitting the bottom of the'pontoon at that 'point and extending the deck I2 outwardly, as indicated at |2a, to join the outer face Ila of the pontoon. The adjacent space between the inner and outer faces of the pontoons is closed by a plate (see Figure 3).

The bottom decks of the inner and outer pontoons are flat, allowing easier erection. Little or no framing is required for this purpose.

Any convenient sealing means between the outer face I3a of the annular pontoon and the side wall 26 of the tank may be employed. A continuous fabric seal 21 of elastic nature is indicated in the drawings.

It will be observed that the bottom of the annular pontoon I3 is well below the bottom of the central pontoon II, and the top of the annular pontoon is above the top of the central pontoon.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom.

What I claim as new. and desire to secure by Letters Patent, is:

A floating roof comprising a central fiat bottom pontoon having a cone roof, an outer substantially annular pontoon having a downwardly and inwardly sloping upper surface forming the top wall thereof and having an inner side Wall and a bottom wall, an annular upstanding rim joined to the top and bottom walls of the outer pontoon and forming the outer wall thereof, an annular deck supported entirely by the central pontoon during normal operation of the roof, said deck sloping outwardly and downwardly from the central pontoon to the annular pontoon and being connected to the inner side wall of said anular pontoon at a point substantially below the top thereof, a broken portion in the top, side and bottom walls of said annular pontoon, said deck extending at said broken portion to the outer rim and being connected thereto, and a drain at thel outer edge of said deck extension.

JOHN W. ALLEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 'Number Name Date 2,193,484 Jones Mar. 12, 1940 2,237,461 Tokhelm Apr. 8, 1941 2,287,213 Wiggins June 23. 1942 2,321,058 Wiggins June 8, 1943 2,430,592 Wiggins --Nov. 1l, 1947 

